Chapter 12

End-to-End Networking

FIGURE 12.0.F01: UDP packet fields.

FIGURE 12.0.F02: UDP header displayed in Wireshark.

© Wireshark Foundation

FIGURE 12.0.F03: Routing and internet protocol layering.

FIGURE 12.0.F04: Major TCP packet fields.

FIGURE 12.0.F05: TCP header displayed in Wireshark.

© Wireshark Foundation

FIGURE 12.0.F06: A TCP connection summarized by Wireshark.

© Wireshark Foundation

FIGURE 12.0.F07: TCP flags displayed by Wireshark.

© Wireshark Foundation

FIGURE 12.0.F08: A “ping” packet shown in Wireshark.

© Wireshark Foundation

FIGURE 12.0.F09: Domain name hierarchy.

TABLE 12.0.T01: Common top-level domain acronyms

FIGURE 12.0.F10: Example format of a three-part domain name.

FIGURE 12.0.F11: Nslookup list of “any” DNS records found for einsec.com.

FIGURE 12.0.F12: Wireshark display of a DNS response.

© Wireshark Foundation

FIGURE 12.0.F13: Looking up a domain name.

FIGURE 12.0.F14: Whois response for stthomas.edu.

FIGURE 12.0.F15: A small LAN connects to its ISP through a single gateway.

FIGURE 12.0.F16: Network address translation: Processing the first packet.

FIGURE 12.0.F17: Configuring a simple gateway product.

© Linksys

FIGURE 12.0.F18: Application filtering on a software firewall.

Screen shot reprinted with permission from Apple Inc.

FIGURE 12.0.F19: Cell phone tower.

Courtesy of Dr. Richard Smith

TABLE 12.0.T02: Dedicated versus dial-up lines

FIGURE 12.0.F20: Tower with a microwave antenna.

Courtesy of Dr. Richard Smith

FIGURE 12.0.F21: Reachability problem.